Drill bit



May 3, 1932. H. M. WHEELER DRILL BIT Original Filed Aug 10, 1929Fatented May 3, 1932 Lasts umrao STATE-S P'ATET OFFICE.

mvn x. nun, or nousron, arms I name Application fled August 10, 1929,Serial No. 384,941.. Renewed larch 7, 1982.

This invention relates to new and useful improvements in a drill bit.

One object of the invention is to provide a drill of the characterdescribed, embodying a head, and detachable cutters secured thereto in anovel manner, the cutter securing means being readily releasable topermit the detachment of the cutters from the headfor repairs orreplacements.

Another object of the invention is to provide a drill having a headformed with spaced prongs and cutting members insertable between the,prongs ofthehead with releasable means. for securing the cuttingmembers. in the head, said securing means also being formed so as to.reeniorce the prongs and to prevent the spreading or distortion thereof.

With the above and other objects in view the invention has particularrelation to certain novel features of construction, arrangement of partsand use, an example of which is given in this specification andillustrated in the accompanying drawings wherein:

Figure 1 shows a side elevation of the drill partly in section.

Figure 2 shows a side view thereof taken at right angles to the viewshown in Figure 1. Figure 3 shows a transverse sectional view taken onthe line 3-.3 of Figure 1, and

Figure 4 shows a fragmentary vertical sectional view taken on the line4-4 of Figure 1. Referring now more particularly to the drawings whereinlike numerals of reference designate similar parts in each of thefigures,

the numeral 1 designates the drill head whose upper end is reduced andformed into an outwardly threaded shank, adapted to receive a drillcollar by means of which the drill may be attached to a drill stem. Thelower end of the head has a deep transverse roove 3 therein, formingsaid lower end into the spaced prongs 4, 4, the outer sides of whoselower ends converge or taper downwardly as v shown in Figure 2. i

There are the cutting members 5, 5 of any desired type, the fish-tailblade type being shown, these cuttin members have the flat shanks 6insertable rom opposite sides of the head into the deep groove 3and-into abutting relation. Each shank 6 has a transverse rib 7 on itsrear side, which fits into a corres onding groove on the inner side of,the ad acent prong 4. @n each side of the head there is a vertical dovetailed groove 8, each groove extending from near the upper end of thehead downwardly to near the lower ends of the prongs 4, and slidablymounted in the respective grooves 8 are the plate like keys 9, 9, whichare provided to lock the cutting members 5 against detachment from thehead. When in their lowered position, the lower ends of the keys 9 abutthe lower ends or the corresponding grooves 8 and rest against theexternal shoulders 10 of said cutting members and said keys are retainedby the set screws 11 which are screwed into the head and abut the upperends of said keys and lock them in position. When the keys are so lockedin place they abut the outer edges of the cutting members 5 and preventtheir detachment.

In order to remove the blades, the set screw 11 may be removed and thekeys 9 elevated and the cutting members 5 then slipped outlaterally fromthe groove 3. The keys 9 have the inwardly turnedmargins 12, 12, asshown in Figure 3, said inwardly turned margins working in thelongitudinal grooves 13, 13 which extend inwardly from the side marinsof the dove tailed grooves 8. When the eye 9 are in position to lock thecutting members 5 in place, these ribs 12 will also serve to reinforcethe prongs and to prevent the same from spreading or becoming distortedunder the strain to which they are subjected by the cutting memberswhile the drill is at work.

The bit head has the usual water courses 1%, 14 leading downwardlyt-herethrough, which extend on down through said prongs and discharge onthe forward sides of the respective cutting members.

The drawings and description disclose what is now considered to bea-preferred form of the invention, butby way of illustration only whilethe broad principle of the invention will be defined by the appendedclaims.

[What I claim is:

1. A drill including a drill head having a transverse end groove formingone end of the head into spaced prongs, cutting means fitted into saidgrooveand projecting out beyond the head, removable retainer plates onthe head, on each side of the cutting means and forming means forsecuring the cutting means against detachment from' the head, ,saidprongs having longitudinal grooves forming seats, and said retalningmeans having longitudinal rojections fitted into said seats and bein eective to secure said prongs against sprea ing.

2. A drill including a, drill head having a transverse groove across oneend thereof forming said end into spaced prongs, cut

ting means seated in said groove between the prongs and extending beyondthe head, retaining means on the head, one on each side of the cuttingmeans, provided to retain said cutting means against detachment from thehead said retaining means comprising keys slidahle on the head intoactive positlon to so retain said cutting means and into inactiveposition to permit the removal of said cutting means for the head, saidhead having longitudinal side keyways, in which the keys are seated, andbeing formed with longitudinal side grooves which extend along theprongs, longitudinal projections on the keys which are fitted into saidprong grooves and are efi'ective to secure the prongs against spreading.

3. A drill including a drill head having a' transverse groove across oneend thereof forming said end into spaced prongs, cutting means seatedin-said groove between the prongs and extending beyond the head,retaining means on the head, one on each side of the cutting means,provided to retain said cutting means against detachment from the headsaid retaining means comprising keys slidahle'bn the head into activeposition to so retain said cutting means and into inactive position topermit the removal of said cutting means for the head, said head havinglongitudinal side keyways, in which the keys are seated, and beingformed with longitudinal side grooves which extend along the prongs,longitudmal projections on the keys which are fitted into said pronggrooves and are effective to secure the prongs against spreading, andreleasable means for locking said keys 1n such active position.

In testimony whereof I have signed my name to this specification.

HARVE M. WHEELER.

